Sometimes you need to get inside your computer to check things out or to get rid of some dust, to keep the airflow clean. Whether it’s a laptop or a desktop, this shouldn’t scare you.
Newer desktop computers are being built with easy-release mechanisms to allow you to take at least one side off. It may be at the top back side or along one side of the release-able side. If there are screws anywhere that you need to remove, and you can tell this by searching the manufacturer’s website, I recommend drawing a diagram of the surface where the screws are and taping each screw onto the diagram relating to the spot you removed it from.
For laptops, this is even more critical, in fact you could even print a photo or a diagram from the manufacturer’s website showing the location of the screws, and tape each screw to its location. After the cover is off, if you have to do any more removal of parts, take a picture or make a drawing of what you’re seeing, so that if you have to take more parts out, you can put them down on your drawing or picture and be able to put them back where they came from.
If you have several pictures or drawings, label them in sequence so that you can put everything back together in the right order, which is going to be the reverse order of how you took it all out. Just pay attention to how it all fits when you put it back together, check the seams, corners, anyplace where stuff connects together. If it looks like it doesn’t fit, work it around (without forcing it) and see if you can get the fit right. If it won’t fit back together, back out the screws and check to see what’s out of place. When everything is where it should be, it’ll all fit back in the way it was when you took the cover off.
If you follow this tip, you don’t have to be scared to take the cover off your computer.